1. Field of the Invention
The present invention relates to an ink fountain divider for an ink fountain arrangement as an ink supply device for a printing press, which is located adapting to a printing region to be used and can store an ink efficiently.
2. Description of the Related Art
Ink fountain dividers for ink fountain arrangements have been disclosed in Japanese Examined Utility Model Publication (Kokoku) No. Showa 50-13123 for "Ink Gate for Rotary Press", Japanese Examined Utility Model Publication No. Showa 50-34089 for "Ink Arrangement for Printing Press" and Japanese Examined Patent Publication No. Showa 36-18722 for "Liquid Vessel Divider".
The "Ink Gate for Rotary Press" disclosed in Japanese Examined Utility Model Publication No. Showa 50-13123, which is used by being placed above an ink flow rate adjusting plate movable for adjusting a gap between an ink fountain and an ink fountain roller, is typically constructed in such a manner that an ink gate body is formed of lead or the like into a cross-sectionally substantially triangular shaped configuration, a magnet is buried in the ink gate body with exposing a magnetic surface on the bottom of the ink gate body, a frame piece of elastic material, such as rubber or the like, is bonded on the outer periphery of the bottom of the ink gate body, and a contact piece of elastic material is bonded on the side contacting with the ink fountain roller. The contact piece is formed with a curved surface for contacting with a part of the outer peripheral surface of the ink fountain roller. The curved surface is formed with a plurality of ridges having a saw-tooth like cross-section and extending in spiral fashion so as to provide frictional resistance against rotation of the ink fountain roller.
The ink gate is magnetically secured on the ink flow rate adjusting plate by the magnet buried in the ink gate body to certainly place at fixed position and maintain thereat so that the lower surface of the frame piece and the lower surface of the contact piece are firmly contacted with the ink flow rate adjusting plate to prevent the ink from causing leakage. On the other hand, the peak portions of respective spiral ridges forming the curved surface of the contact piece are kept in contact with the outer periphery of the ink fountain roller and, when the ink fountain roller is driven to rotate for feeding the ink, respective ridges keep frictional contact with the outer periphery of the ink fountain roller to be pulled in spiral direction to make the lower tip ends thereto to penetrate into a gap defined between the ink fountain roller and the ink flow rate adjusting plate, and in conjunction therewith, the curved surface of the contact piece keeps firm contact with the outer peripheral surface of the contact piece for preventing leakage of the ink.
On the other hand, in the construction of the "Ink Arrangement of Printing Press" as disclosed in Japanese Examined Utility Model Publication No. Showa 50-34089, an ink gate to be placed on an ink doctor forming a bottom plate of the ink arrangement in an ink supply device, in which adjustment of a gap with respect to the ink fountain roller is performed by deforming the ink doctor in a direction of angular displacement by pushing up an adjusting screw, is formed with an ink gate body formed of an elastic rubber for conformability and for avoiding damaging of the ink doctor and the ink fountain roller, and a rubber magnet plate is mounted at the portion mating with the ink doctor. When adjustment is made by pushing up the ink doctor, the ink gate formed of rubber and the rubber magnet plate bonded on the lower surface of the ink gate may be deformed in conformance with deformation of the ink doctor to keep firm contact with the latter over the entire contacting surface to successfully prevent leakage of the ink.
Also, "Liquid Vessel Divider" disclosed in Japanese Examined Patent Publication No. Showa 36-18722 is an ink fountain divider which is disposed in an ink vessel perpendicularly to the ink vessel and an ink vessel roller. A sealing elastic plate of an elastic material, such as rubber or the like, for preventing leakage of the ink is clamped by side plates at both sides. A metallic pressure plate which is formed into a shape conforming with the shapes of the ink vessel roller and the inner wall of the ink vessel, is provided on the periphery of the inside of the sealing elastic plate for depressing the sealing elastic plate onto the ink vessel roller and the inner wall of the ink vessel by a uniform pressure. Also, on the opposite side of the sealing elastic plate across the metallic pressure plate, a connecting member is provided at a position distanced from the metallic pressure plate substantially equal distance to that of the sealing elastic plate. A plurality of compression springs are mounted between the metallic pressure plate and the connecting member for depressing the metallic plate with a regular interval. A mounting hook and clamp are connected to one end of the connecting member for placing the ink fountain divider at desired position in the ink vessel.
Once the ink fountain divider is fixed within the ink vessel by means of the mounting hook and the clamp, the sealing elastic plate contacts with the ink vessel roller and the inner wall of the ink vessel to be pushed back against the compression spring. Associating therewith, the sealing elastic plate is pushed outwardly via the metallic pressure plate by reactive force of the compression springs. By this, the ink fountain divider can firmly contact with the ink vessel roller and the bottom plate of the ink vessel to prevent leakage of the ink.
The foregoing prior arts hold several drawbacks to be solved. Namely, in the "Ink Gate for Rotary Press" as disclosed in Japanese Examined Utility Model Publication No. Showa 50-13123, the magnet is buried in the ink gate body formed of lead or the like, the frame pieces of elastic material is bonded on the outer periphery of the bottom surface, and the contact piece of elastic material, such as rubber or the like, formed with a plurality of ridges formed into spiral fashion for contacting with the ink fountain roller as rotated, on the side contacting with the ink fountain roller.
Since the ink gate is used by positioning on the ink flow rate adjusting plate for adjusting gap defined between the ink fountain roller, a pressure is applied to the contact piece having a plurality of ridges extending in spiral fashion with the curved surface formed with the elastic material on the side contacting with the ink fountain roller for constantly keeping frictional contact on the outer peripheral surface of the ink fountain roller even when the ink gate is shifted, for preventing leakage of the ink. However, since the contact piece of elastic material, such as rubber or the like is constantly kept in frictional contact with the rotary body, i.e. the ink fountain roller, the portion of the contact piece contacting with the rotary body can be quickly worn to shorten the life of the product. On the other hand, the force contacting the ink gate onto the ink flow rate adjusting plate is determined by the weight of the lead or the like as own weight and a magnetic force of the magnet buried in the lower surface. However, the force is not large for permitting mounting and releasing of the ink gate by a worker. When the stored ink is stirred by the ink gate, the ink gate is subject to the pressure from the ink being stirred and the spiral ridges at the tip end of the contact piece are subject to frictional resistance in the spiral direction by rotation of the ink fountain roller to possibly cause displacement of the ink fountain roller in a direction widening the ink storage region to be a cause of ink leakage. Also, since the ink gate is formed of relatively heavy material, such as lead or the like, work load in mounting, releasing and transporting on the worker becomes heavy to possibly cause damage on the shoulder, lumbar area or so forth. Furthermore, the ink gate can be dropped down from the worker's hand due to heavy, thus requiring other safety measures.
On the other hand, in "Ink Arrangement for Printing Press" disclosed in Japanese Examined Utility Model Publication No. Showa 50-34089, adjustment of the ink flow rate is performed by deforming the ink doctor in the direction of angular displacement. The ink arrangement includes the ink gate body made of an elastic body having flexibility conformable with deformation of the ink doctor, and the ink gate means of the rubber magnet mounted on the lower surface of the ink gate.
The ink gate body is formed of rubber having elasticity for high conformability with the ink doctor and not damaging the ink fountain roller. According to deformation of the ink doctor, the ink gate body is also deformed in conformance therewith to contact with the ink fountain roller under pressure. Therefore, the portion of the ink gate body contacting with the ink fountain roller is quickly worn to shorten the product life. The force to keep the ink gate contact with the ink doctor is only magnetic force of the rubber magnet mounted on the lower surface of the ink gate, which force is in a magnitude permitting mounting and releasing of the ink gate by worker. When the stored ink is stirred by the ink gate means, the ink gate is displaced in the axial direction of the ink fountain roller in the direction of widening the ink storage region by the pressure exerted by the stirred ink to be a cause of ink leakage.
Furthermore, in "Liquid Vessel Divider" disclosed in Japanese Unexamined Patent Publication No. Showa 36-18722, the ink fountain divider is disposed within the ink vessel substantially perpendicularly to the ink vessel and the axis of the ink vessel roller to firmly contact therewith to avoid ink leakage. The ink fountain divider prevents leakage of the ink by outwardly pushing the sealing elastic plate located outside and formed of elastic material, such as rubber or the like, by a pressurizing mechanism constituted of the connecting member disposed within the ink fountain divider, the compression springs and the metallic pressure plate.
The sealing elastic plate of the ink fountain divider is formed of elastic material, such as rubber or the like and is constantly contacted with the ink vessel roller to be quickly worn to shorten the product life. Also, the pressurizing mechanism for the sealing elastic plate is constructed with the connecting member, the compression springs and the metallic pressure plate and thus is complicated in structure, requires a large number of parts resulting in high cost. Furthermore, possibility of occurrence of failure is high.